Treatments for castration-resistant prostate cancer

Castration-resistant prostate cancer (CRPC) is cancer that continues to grow even when the testosterone levels are at or below the castrate level. It can also be called hormone-refractory or hormone-resistant prostate cancer. Non-metastatic castration-resistant prostate cancer has not spread to other parts of the body (based on bone scans and CT scans). Metastatic castration-resistant prostate cancer has spread to lymph nodes or other parts of the body, such as the bones.

Your doctor will know that you have castration-resistant prostate cancer if a blood test shows that your prostate-specific antigen (PSA) level is rising and your testosterone level is low. Imaging tests may also show that the cancer has started to grow. Doctors may look at the PSA doubling time to help decide on treatment. PSA doubling time is the time is takes for the PSA level to double.

The following are treatment options for non-metastatic castration-resistant prostate cancer. Your healthcare team will suggest treatments based on your needs and work with you to develop a treatment plan.

You will usually continue with some type of hormone therapy if the PSA level is rising but there are no other signs of prostate cancer. Hormone therapy changes the levels of hormones or blocks certain hormones to slow the growth and spread of cancer cells.

You may be observed with your current hormone therapy injection or another pill form of hormone therapy may be added, such as:

• an anti-androgen – apalutamide (Erleada), enzalutamide (Xtandi) or darolutamide (Nubeqa)

If you are already taking an anti-androgen, sometimes the prostate cancer will stop growing for a while if you stop the anti-androgen therapy.

Find out more about hormone therapy for prostate cancer.

Treatments for metastatic castration-resistant prostate cancer are mostly to slow the growth of cancer cells, relieve your symptoms, improve your quality of life and help you live longer.

The following are treatment options for metastatic castration-resistant prostate cancer. Your healthcare team will suggest treatments based on your needs and work with you to develop a treatment plan.

You may continue with some type of hormone therapy if the PSA level is rising but there are no other signs of prostate cancer. Hormone therapy changes the levels of hormones or blocks certain hormones to slow the growth and spread of cancer cells. Hormone therapy and chemotherapy may be used together.

You may be observed with your current hormone therapy and other hormone therapies may be added such as:

• an anti-androgen – apalutamide (Erleada) or enzalutamide (Xtandi)

• an androgen synthesis inhibitor – for example, abiraterone (Zytiga)

If you are already taking an anti-androgen, sometimes the prostate cancer will stop growing for a while if you stop the anti-androgen therapy.

Find out more about hormone therapy for prostate cancer.

Chemotherapy may be used to treat metastatic castration-resistant prostate cancer that is causing symptoms. It uses anticancer drugs to destroy cancer cells. The chemotherapy drugs most commonly used are docetaxel with prednisone. But if docetaxel and prednisone are no longer working, you may be given cabazitaxel (Jevtana) or mitoxantrone.

Other chemotherapy drugs that may be used include:

• paclitaxel
• etoposide (Vepesid)
• vinblastine

Find out more about chemotherapy for prostate cancer.

Targeted therapy uses drugs to target specific molecules (such as proteins) on cancer cells or inside them to stop the growth and spread of cancer and limit harm to normal cells. Targeted therapy may be used to treat metastatic castration-resistant prostate cancer that has certain genetic mutations.

Targeted therapy drugs that may be used include:

• olaparib (Lynparza)
• niraparib combined with abiraterone acetate (Akeega)

Find out more about targeted therapy for prostate cancer.

Radiation therapy may be offered to sites that are causing symptoms. It uses high-energy rays or particles to destroy cancer cells.

External radiation therapy is the type of radiation therapy most often used. It is often given together with hormone therapy. External radiation therapy may be used:

• as the main treatment to destroy cancer cells
• to relieve urinary (peeing) problems caused by the tumour
• to relieve pain where the cancer has spread to the bones (called bone metastases)

Systemic radiation therapy with radium-223 dichloride (Xofigo) may be used to treat castration-resistant prostate cancer that has spread to the bones.

Find out more about radiation therapy for prostate cancer.

When prostate cancer spreads to other parts of the body, it most often spreads to the bones. The most common treatments for prostate cancer that has spread to the bones are:

• bisphosphonates, such as zoledronic acid (Zometa)
• denosumab (Xgeva), which is a type of monoclonal antibody therapy
• corticosteroids, such as prednisone and dexamethasone
• external radiation therapy
• systemic radiation therapy with radium-223 dichloride (Xofigo)
• a procedure to stabilize a collapsed bone (called kyphoplasty)
• pain medicines

Find out more about bone metastases, including treatments and supportive therapies.

You may want to consider a type of care to make you feel better without treating the cancer itself. This may be because the cancer treatments don’t work anymore, they’re not likely to improve your condition or they may cause side effects that are hard to cope with. There may also be other reasons why you can’t have or don’t want cancer treatment.

Talk to your healthcare team. They can help you choose care and treatment for advanced cancer.

Talk to your doctor about clinical trials open to people with prostate cancer in Canada. Clinical trials look at new ways to prevent, find and treat cancer. Find out more about clinical trials.

PSA testing and imaging tests may be done regularly to see if the cancer has grown or spread. Find out more about follow-up tests.